D
Circumference of a circle = 2πr, where r is the radius of the circle. So, a circle with a circumference of 36π has a radius of
25.
G
The perimeter of the square is 36, and since all four sides are equal, one side has length 9. Since the circle is inscribed in the
square, its diameter is equal in length to a side of the square, or 9. Circumference is πd, where d represents the diameter, so
the circumference of the circle is 9π.
26.
B
A circle contains 360º, so
27.
J
The area of a square is equal to the length of one of its sides squared. Since one of the vertices (corners) of the square lies on
the origin at (0, 0) and another vertex lies on the point (−2, 0), the length of a side of the square is |−2 − 0| = |−2| = 2.
Therefore, the area of the square is 22 = 4.
28.
C
While there is no way to determine the numerical values of a, b, c, and d from their positions on the coordinate plane, you do
know that a is negative, b is positive, c is negative, and d is negative. Bearing in mind that a negative times a negative is a
positive, consider each answer choice. Choice (C) is indeed true: b, which is positive, is greater than acd, which is negative.
29.
F
The points (0, 6) and (0, 8) have the same x-coordinate. That means that the segment that connects them is parallel to the y-
axis and that all you have to do to figure out the distance is subtract the y-coordinates: |8 − 6| = 2. So the distance between the
points is 2.
30.
E
OP is the radius of the circle. Since O has coordinates (0, 0), the length of OP is |4 − 0| = |4| = 4. The area of a circle is πr^2 ,
where r is the radius, so the area of circle O is π(4)^2 = 16π.
31.
H
Right triangle ABC has legs of 6 and 8, so its hypotenuse must be 10. Notice that the hypotenuse is also the diameter of the
circle. To find the area of the circle, we need its radius. Radius is half the diameter, so the radius of circle P is 5. The area of
32.
